Nannostomus mortenthaleri (Coral Red Pencilfish, Nannostomus sp. "Peru Red", Nannostomus marginatus mortenthaleri)
One of the most brilliantly coloured pencilfish. Only recently described by science (see Weitzman & Weitzman 2002) following discovery a couple of years before in the Rio Nanay, Peru.
Initially believed to be a variant of Nannostomus marginatus it can be distinguished from that species by its slightly larger size and more robust build. In breeding condition especially, the fish are also dramatically more brightly coloured. Males display thick, bold red banding from the snot to the base of the tail fin. Females and immature males are less strongly coloured and quite similar in appearance, but males have a distinctive white patch at the bottom of the leading edge of the dorsal fin.
Fish information (behaviour and breeding):
A superb fish for either a quiet community tank or for use on its own in an Amano-style planted aquarium. Can be delicate immediately after import, but will settle down quickly if given the correct water chemistry and ample live foods such as daphnia, brine shrimp and mosquito larvae. Accepts frozen alternatives such as bloodworms willingly, but flake is a bit less popular.
As with other pencilfish, this species is quiet and easily bullied by more aggressive or fast-moving species. On the other hand, in small groups the males can be nippy towards one another. Should always be kept in a fair sized group, ideally at least ten specimens.
Has been bred in aquaria. Very soft (general hardness around 20 ppm) and slightly acidic (pH 6.6) water is required.
|Distribution||South America: Peru|
|Size||Up to 4 cm|
|Water Parameters||Soft and slightly acidic water recommended|
|Water Chemistry||less than pH 7 - acidic|